A New Attitude Estimation Method of Space Target Utilizing ISAR Image Sequence Under Low SNR

Given the prior geometry model, the attitude of a space target can be estimated by evaluating the target contour similarity between the practical inverse synthetic aperture radar (ISAR) image sequence and the theoretical projection images. However, the target will be submerged in the noise under low signal-to-noise ratio (SNR), resulting in inaccurate target contour extraction and attitude estimation. In view of this, a new attitude estimation method is proposed by optimizing the projection area energy accumulation value along the ISAR image sequence. The projection area energy accumulation (PAEA) value will reach the maximum when the attitude candidate of the prior geometry model corresponds to the true one. Particle swarm optimization (PSO) algorithm is utilized to improve the search efficiency. The proposed method is more robust to the noise because of the utilization of target energy instead of the target contour. Experimental results verify the effectiveness of the proposed method.